Sight for ships  qu-ms



(No Model.)

2 Sheets -Sheet 1. B. A. FISKE. TELBSOOPIG SIGHT FOR SHIPS GUNS.

Patented Sept. 5, 1893.

J] WIT/M8858: v my,

@QWZZQV J9. Ey 7) "Br ATTORNEY.

(No Model.) I 2 Sheets-Sheet 2.

B. A. FISKE.

TELESGOPIO SIGHT FOR SHIPS GUNS. No. 504,337. Patented Sept 5, 1898.

disses Farmer which...

TELESCOPEQ SE'GHT FOR $HlPS SPEGXFZGATIGH forming part of Letters Patentfhl'o. 504,337, dated September 5, 1893.

Application filed March 9, 1891.

.10 wi l whom may concern.-

Be it known that I, BRADLEY ALLAN FISKE, of the United States Navy, haveinvented a new and useful Improvement in Telescopic Sights for ShipsGuns, of which the following is a specification.

In Letters TatentNo. 435,925, granted to me on the 9th day of September,1890, I have fuiiy set forth my method of pointing a gun located onrolling, heeling,or vibrating platform, which method consists inadjusting a telescope also located on said platform and movable on atransverse axis approximately parallel to that of the gun at an angle tothe axis of the bore of said gun equal toa certain predetermined angleof elevation necessary to cause the projectile fired from said gun totravel to a given target, and then noting the moment when the line ofsight of said adjusted telescope is caused by the movement of saidsupporting platform to intersect said target.

My present invention relates to an apparatus for carrying said methodinto practical effect, and consists more particularly in theconstruction of a telescopic sight for ships guns as hereinafter setforth and in the combiuation of the same with thegun.

in the accompanying drawings, Figure 1 illustrates diagrammatically agun disposed with the axis of its bore parallel to the plane of theships deck and provided with a shield, upon which is mounted myaforesaid telescopic sight, which is shown in two positions; namely,with the axis of the telescope parallel to the gun axis, with the axisof the telescope placed at an. angle to said gun axis. Fig. 2 representsthe same parts as in Fig. 1,and shows how the telescope is brought intohorizontal position after it has been adjusted at an angle, asaforesaid, by the rolling or pitching of the vessel, whereby the deckassumes an in: clincd position. Fig. 3 is an elevatio'n of my telescopicsight showing certain parts broken away and in partial section. Fig. 4is a face view of the graduated disk and stationary surrounding limbwhich is graduated in degrees and fractions.

Similar letters of reference indicate like parts.

Referring first to Figs. 1 and 2, A represents portion or" a ships deck.

13 is the gun, the trunnions C of which are Serial No. 384,218. (Nomodel.)

mounted upon any suitable carriage D sup ported on .a slide whichcarries the usualprotecting shield E, through an opening in which 5 arereceived in suitable bearings carried by standards K which rise from thebase G.

- Extending downward from the middle part of the telescope H is aprojection L, the lower extremity of which is cutaway to form a verticalfiat surface, against which surface bears the point of the adjustingscrew M. The screw M passes through a threaded standard N upon the baseG; and upon its shaft carries a flanged disk 0, and also outside of saiddisk a milled head P, by means of which head P said screw is turned.

Supported by bars Q projecting from 'the standards K, is an arc-shapedlimb R, which has its inner periphery in close proximity to thecircumferential edge of the disk 0.

Connected to the projection L and extending downward below the same, isan arm S to which is secured one end of acoiled spring T; the' other endof said spring being fastened to a hook, or otherwise secured upon thepost N.

The telescope His of the usual kind for field work and is provided withsuitable crosshairs. Upon the disk Ois marked firstazero point, and thenfollow regular graduations, suitably marked, as shown in Fig. 4, whichindicate yards of range. The markings upon the limb It represent degreesof elevation or depression of the telescope.

The general operation of my aforesaid apparatus willbe understood fromFigs. 1 and 2, and also from the statements contained in mydbOVGJlELIIlBQ patent. Referring first to Fig. 1, here the axis of thebore of the gun represented by the dotted line a a, is shown to beparallel to the plane of the deck A. The line of sight of the telescopelI (fuli lines) is shown by the dotted line b I), which is parallel tothe line (to. Let it now be assumed that the gun is to be given acertainelevation necessary to carry the projectile over a given range orinterval between the said gun and the target. Ordinarily this is done byadjusting a vertically moving sight bar supported upon the breech of thegun so that a notch thereupon will be properly elevated, and thenlowering the breech of the gun until the line of sight of the persondirecting said gun includes the bottom of said notch, the top of a fixedsighting pointlocated upon the gun body and the object. When thisoccurs, the muzzle of the gun will have been raised over a certainangle; or in other words, the gun will have been elevated over an anglesufiicient to cause the projectile to travel over the given range orinterval. In practice, it is customary to mark the ordinary sight barboth in degrees and fractions, so that the gun may be set at any desiredelevation, and also for yards of range corresponding to the elevation indegrees; so that,

by means of said sight-bar, the gun may be adjusted in elevation to anydesired angle, or for any desired range. The objections to this form ofsight upon ships guns are numerous. Inasmuch as the sight-bar is uponthe gun itself, it partakes of all motions of- The bar after the gun;such as the recoil. adjustment is, therefore, liable to displace ment,and in fact is usually readjusted for each shot. The person sighting thegun is obliged to stand at a distance from the breech and hence from thesight bar; thus greatly increasing the difilculty of bringing the rearsight and front sight of the gun and the object into line. Thesedifficulties are much enhanced when the ship (as is invariably the caseat sea) is rolling or pitching. The person sighting the gun must thenmaintain his own equilibrium, and in addition must seize the exactmoment when the sights come .in line with object, to fire. Theconsequence is that accurate firing in a sea-way has become largely amatter of individual skill, which may require high development notmerely by reason of the difficulties before noted, but for theelimination of personal equation of error, as well as for its employmentunder the exciting conditions ofactual conflict. By my presentinvention, the aforesaid difliculties are greatly reduced, and to alarge extent overcome. In accordance with the method described in myprior patent, I employ primarily the rolling or pitching of the shipitself to give to the gun the necessary elevation; the piece beingnormally laid with the axis of its bore parallel to the deck; or, if theextent of angular movement of the deck is not sufficient to carry thegun over the whole desired angle of elevation, then I give to the gun bythe ordinary elevating gear, a

- certain initial angle of elevation which is made sufficiently great toallow of'the ships movement completing the whole desired angle. I also,in accordance with my aforesaid method, effect the sighting of the gunby means of a telescope not supported on the gun, nor partaking of theguns recoil.

present invention I support the telescope H, as shown in Figs. 1 and 2,preferably upon the To this end, in my the shield, is so trained at thesame time.

telescope being attached to The observer at said telescope notes thefact i that the target, as the ship rolls, is seen at the intersectionof the cross-wires. The object end of the telescope is then depressed bythe means hereinafter detailed over an angle which is to equal that ofelevation of the gun necessary to cause the projectile to travel overthe distance or range between gun and target. The position of thetelescope when so depressed is indicated by the dotted lines in Fig. 1,and the direction of its line of sight by the line 0 c. The observerstill keeping his eye at the telescope, then watches for the target oncemore to appear at the intersection of thecross-hairs. This obviouslywill occur when the deck A, and hence the axial line a a of the gun,assume an angle equal to that at which the telescope has been placed; orin other words, when the telescope H be comes horizontal, as indicatedin Fig. 2, then the axis of the bore 'a a will stand at the proper angleto give the projectile the required range. The observer therefore, assoon as he notes the coming of the target upon the intersection of thecross-Wires, presses the firing key and discharges the gun.

Referring now to Figs. 3 and 4, I have here illustrated the mechanismwhich practically supersedes the ordinary sights on the gun. It will beplain that when the milled head P is turned in one direction, the pointof screw M pushing upon the extremity of the projection L, causes theobject end of the telescope to rise; but when said milled head is turnedthe other way, the spring T acting upon the arm S and projection L,causes the object end of the telescope to descend. Therefore thetelescope may be elevated or depressed by turning said head P, which isplaced to the hand of the operator. mark on the disk 0 is so placed thatwhen it coincides with the zero mark on the limb R, the line of sight ofthe telescope is parallel to the deck. The limb R is marked to representdegrees of angular motion of the telescope; and upon the disk 0 aremarked the ranges which correspond to those angles and which will begiven by the gun which the apparatus is to control. Thus in Fig. 4, itis shown that at an angle of elevation of two degrees the range will betwo thousand two hundred yards. At an angle of one and a half degrees,the range will be aboutsixteen hundred and seventy-five yards. At onedegree, ten hundred and seventy-five yards, and so on. If, therefore, wewish to adjust the telescope for a range say of two thousand twoh'undredyards,' the milled head P is turne until the mark two thousandtwo hundred comes opposite the zero mark on the limb R. The spring Tacting on the projection L, will then have depressed the telescope overan arc of two degrees. A similar operation is performed for any otherrange mark on the disk 0: it being necessary simply to bring the properrange mark into coincidence with the zero mark on the limb R to knowthat the telescope has been set at such an angle as that when the objectappears at the intersection of its cross-hairs, the gun itself locatedin proximity to that telescope wiil be at the same angle; 0'! in otherwords, he so adjusted as to throw its projectile over the rangeindicated by the disk. In case the ship is not rolling or pitchingsuiiiciently to give to the gun the desired elevation, then, as alreadydescribed, an initial elevation is given to the gun itself; say, forexample, one degree, when the total required angle is two degrees. Itwill be obvious then that the necessary angular movement of thetelescope will be only one degree for a range, say of two thousand twohundred yards. In such case, therefore,

the two thousand two hundred mark on the disk 0 is not moved around tothe zero point on the limb R, but to the one degree point on said limb;'or in other words, to the point representing the initial elevation givento the gun whatever it may be. -By the word deck is herein meant thatpart of the deck on which the gun moves and which in modern war ships isalways a plane surface. The line from the gun to that point of a targetsituated at the same height above the water as the. gun, is here assumedas the line of sight, and the line of sight is thus assumed to behorizontal. But it is evident that no appreciable error is introduced ifthe line of ght be not exactly horizontal, but intersect a target on thewater at any point, for the projectile will simply strike the targethigher 01' lower according as theline of sight is higher or lower. It isevident that for night firing, thecross hairs may be made incandescentby an electric current, as is done with astronomical telescopes, thusavoiding the necessity for the complicated electrical night sights usedin all the navies of the world.

I claim I 1. The combination of a gun asupport laterally movable withsaid gun, and a sight tube mounted on said support,- the said tube andthe said gun being independently movable on their transverse axes inparallel vertical planes.

2. The combination of a gun mounted on a vibrating platform, asupporting carriage therefor, a protecting shield for said gun andcarriage and a sight tube supported on said shield; the said tube andthe said gun being independently movable on their transverse axcsinparallel vertical planes.

3. The combination of a gun mounted on a vibrating platform, a supportlaterally movable withv said gun, a sight tube mounted on said sup port(the said tube and the said gun being independently movable on theirtransverse axes in parallel vertical planes) and means for adjustingsaid tube to desired angles of elevation or depression.

4. The combination of a gun mounted on a vibrating platform, a supportlaterally niovable with said gun, a sight tube mounted. on said support(the said tube and 'the said gnu being movable on their transverse axesin. parallel vertical planes) means for adjusting said tubes to desiredangles of elevation or depression and an index showing the extent ofsaid angular movent.

The combination of ages mounted on a vibrating platform, a supportlaterally mov able with said gun, a sight tube mounted on said support(the said'tube and the said gun being movable on their transverse axesin parallel vertical planes), means for adjusting said tube to desiredangles of elevation or depression, and an index showing the range of thesaid gun when laid at corresponding angles.

6, The combination of a gun mounted on a vibrating platform, a supportlaterally movable with said gun, a sight tube mounted on said support(the said tube and the said gun being movable on their transverse axesin parallel vertical planes), means for adjusting said tube to desiredangles of elevation or depression, an index showing the extent of saidangular movement, and an index showing the range of said gun when laidat correr spending angles.

7. The combination of a sight tube movable on a transverse axis, a screwoperating to cause said motion, a graduated disk carried by said screw,and an index or scale plate in proximity to said screwindex, the diskand the plate being graduated one in angles and the other in the rangescorresponding thereto.

8. The combination of a sight tube movable'on a transverse axis, a screwoperating to cause said motion in one direction, and an opposing springoperating to cause said motion in the other direction, an index carriedby said screw, an index or scale plate in proximity to said screw index,and showing the extent of rotation of said screw and hence of theangular movement of said sight tube. V 9. The combination ofthetelescope ll supported on its transverse axis and having theprojection L, the adjusting screw M bearing upon said projection andoperating to move said telescope on its axis in one direction,

means; such as a retracting spring for moving said telescope in theopposite direction, a disk 0 on the screw shaft and provided with anindex and a fixed scale R in proximity to said disk and showing theextent of rotation of said screw, and hence of the angular movement ofsaid telescope.

10. The combination of ,the telescope H supported on its transverse axisand having the projection L, the adjusting screw M, bean ing uponsaidprojection and operating to said disk and showing the extent ofrotation of said screw and hence the angular moveto ment of saidtelescope.

BRADLEY A. FISK E.

Vitnesses:

R0131. M. IIOOPER, ARTHUR ELLALOIS.

